\documentclass[aspectratio=169,draft]{ctexbeamer}
\usetheme[blue,light,shadow]{sjtubeamer}
\begin{document}

%\include{intro.tex}

\include{middle.tex}
% \begin{frame}
% \frametitle{如何套用 SJTUBeamer？}
% 非常简单，只需 \texttt{\textbackslash{}
% usetheme\{sjtubeamer\}} 即可。
% \end{frame}

%\include{end.tex}

\end{document}